- An infant hears their mother's voice and sweetly coos at this sound. The infant knows the voice and thereby feels comforted. However, a loud crash from a broken dish will likely result in crying as the infant has not heard this sound before and so is not able to interpret it.
- A toddler delights in hanging upside down on a swing, rolling in the grass and practicing somersaults with his mom. This child is enjoying the sensations of the vestibular system (more coming on this and the other sensory systems in upcoming posts) which primes the nervous system to feel where the body is in space. Learning through doing is one of the ways the sensory information gets processed.
- A 4 year old boy tastes a slice of lemon for the first time. He puckers and says "wow!" indicating that the flavor is much stronger than anything he has tasted before. He starts crying and immediately grabs for his water cup to wash the flavor from his mouth.
- A ten year old boy rides a roller coaster, bombarding him with sounds, sights from high off the ground and a jarring ride. He screams with joy throughout the ride and begs his mom to go on the ride again.
- A teenager goes into the cafeteria at her middle school and can smell right away they are having pizza that day. She sprints to the line because she is so hungry and pizza is her favorite.
- A weary mom pulls into her driveway after a long day at work. Although it is dark outside, she sees her family buzzing about inside, talking to each other and she can hear loud music playing. She closes her eyes, turns off the car and sits in the quiet for 5 minutes so she can gather herself before she goes inside.
All of these experiences involve the introduction of a sensory input, followed by a behavioral response. The response is generated as a result of the person determining whether the input is something that feels good or something that may not feel as good. Sensory experiences are very tied to our emotions, or in neuroscience terms, our limbic system. The limbic system has an excellent "memory" and can recall our preferences very readily. For example, although the ten year old boy did not ever have the experience of riding a roller coaster, he probably has had some very positive experiences on the playground, in the climbing gym or at gymnastics class which have told his nervous system that this type of movement and noise is fun. Conversely, the mom in the last example knows exactly how loud and bright her house will be when she walks in. She chooses to get herself in a calm state through a brief respite in the car so she feels recharged before entering.
Sensory experiences also spark learning. In any of these examples, the person is learning as a result of the sensation they are encoding. Why is the lemon so strong, Mommy? Where did that noise come from? Maybe if I move quickly enough I'll be first in line for that pizza. Perhaps a moment of quiet will help me transition from work to home better. Kids are learning not only the "why's" of the senses, but their own preferences. We all have preferences for the types of sensory experiences, or "input" that we prefer. But only by experiencing a wide variety of sensory input do we achieve the fundamentals of learning, adapting and preferring.
Do we experience only one sense at a time? Rarely. Our senses can work together in order to help us best understand what is happening. In the first example, when the infant hears her mother's voice, she is also likely being held (proprioception or "touch" sense) and also maybe rocked (vestibular sense) which are also both very comforting. We are likely experiencing many different senses at once at any given time. While you are asleep, your senses are not as heightened as when you are awake, but any of your senses can cause you to wake up. All moms know that their hearing becomes more acute after they bring a new baby home. So, your senses never really "shut off." Even so-called sensory deprivation tanks make use of some of your senses!
In follow up articles, we will explore the senses in depth and discuss how you can develop each one in your child-and maybe even yourself.